Cranes and other vehicles that are utilized in cargo port operations may utilize some form of navigation system help provide location information within the cargo port. Such a navigation system may comprise a satellite navigation system, such as a GNSS system. The GNSS system may be paired with an inertial navigation system (INS) for improved accuracy. The combined GNSS/INS system provides current location and navigation information that may be utilized by the driver of the vehicle to navigate throughout the cargo port environment. The INS system may aid in navigation if the GNSS system loses accuracy, which may occur when, e.g., multipath situations occur. A multipath situation occurs when, e.g., signals transmitted from GNSS satellites are reflected by local terrain and/or buildings, thereby resulting in a plurality of signals being received by the GNSS receiver. Due to the plurality of signals being received, each of which may be phase shifted and/or time delayed, the GNSS receiver may not be able to accurately detect its location. In an exemplary cargo environment, a plurality of cargo containers may be stacked, thereby creating an obstruction that may result in additional multipath signals. As will be appreciated by those skilled in the art, the plurality of stacked containers located within a typical cargo port environment may create a significant multipass impediment to a GNSS system.
Vehicles utilized in a cargo port environment may include, e.g., cranes, forklifts, etc. Typically they are operating in a low dynamic capacity which generally means that the vehicles are operating at a low velocity and/or experiencing small dynamic sensations. In low dynamic environments, an INS system may not provide accurate navigation information to a combined GNSS/INS system. Thus, if the GNSS system loses accuracy, such as due to entering a multipath environment, the overall navigation system for the vehicle may be severely hindered in its accuracy.